We had a fantastic stay at Nui's apartment.
The flat was modern, immaculate and a perfect size for 2 people. It rivals a luxury hotel (the shower is the best) with a nice little gym, easy to use laundry room and a pool if you fancy it. Nui made sure we knew exactly where the flat was and how best to get there from the airport. He also gave us some handy tips and local knowledge to help us settle in.
The location was great - only 5 minutes from the BTS station from which you could get anywhere quickly (about 20 minutes to Siam). Outside there was a great food market (called W) which had a great atmosphere and about 20 food vendors to choose from (also served as a gentle introduction into street-food). There is also a 7/11 1 minute away and plenty of great coffee shops.
Would highly recommend!